<template>
  <div>
    <el-breadcrumb separator-class="el-icon-arrow-right">
      <el-breadcrumb-item :to="{ path: '/welcome' }">首页</el-breadcrumb-item>
      <el-breadcrumb-item>商品管理</el-breadcrumb-item>
      <el-breadcrumb-item>参数列表</el-breadcrumb-item>
    </el-breadcrumb>
    <!-- 卡片视图区域 -->
    <el-card>
      <!-- 警告区域 -->
      <el-alert
        title="注意：只允许为第三级分类设置相关参数！"
        type="warning"
        :closable="false"
        show-icon
      >
      </el-alert>
      <!-- 选择商品分类区域 -->
      <el-row class="cate_opt">
        <el-col>
          <span>选择商品分类：</span>
          <!-- 商品分类的级联选择器 -->
          <el-cascader
            v-model="selectedKeys"
            :options="cateList"
            :props="cateProps"
            @change="handleChange"
          ></el-cascader>
        </el-col>
      </el-row>
      <!-- tag 页签区域 -->
      <el-tabs v-model="activeName" @tab-click="handleTabClick">
        <!-- 添加动态参数的面板 -->
        <el-tab-pane label="动态参数" name="many">
          <el-button
            type="primary"
            size="mini"
            :disabled="isBtnDisabled"
            @click="addDialogVisible = true"
          >
            添加参数
          </el-button>
          <!-- 动态参数表格 -->
          <el-table :data="manyTableData" stripe border>
            <!-- 展开行 -->
            <el-table-column type="expand">
              <template slot-scope="scope">
                <!-- 循环创建标签 -->
                <el-tag
                  v-for="(item, i) in scope.row.attr_vals"
                  :key="i"
                  closable
                  @close="handleClosed(i, scope.row)"
                >
                  {{ item }}
                </el-tag>
                <!-- 动态编辑标签 -->
                <el-input
                  class="input-new-tag"
                  v-if="scope.row.inputVisible"
                  v-model="scope.row.inputValue"
                  ref="saveTagInput"
                  size="small"
                  @keyup.enter.native="handleInputConfirm(scope.row)"
                  @blur="handleInputConfirm(scope.row)"
                >
                </el-input>
                <el-button
                  v-else
                  class="button-new-tag"
                  size="small"
                  @click="showInput(scope.row)"
                  >+ New Tag</el-button
                >
              </template>
            </el-table-column>
            <el-table-column type="index"></el-table-column>
            <el-table-column
              label="参数名称"
              prop="attr_name"
            ></el-table-column>
            <el-table-column label="操作">
              <el-button type="primary" size="mini" icon="el-icon-edit">
                编辑
              </el-button>
              <el-button type="danger" size="mini" icon="el-icon-delete">
                删除
              </el-button>
            </el-table-column>
          </el-table>
        </el-tab-pane>
        <!-- 添加静态属性的面板 -->
        <el-tab-pane label="静态属性" name="only">
          <el-button
            type="primary"
            size="mini"
            :disabled="isBtnDisabled"
            @click="addDialogVisible = true"
          >
            添加属性
          </el-button>
          <!-- 静态属性表格 -->
          <el-table :data="onlyTableData" stripe border>
            <!-- 展开行 -->
            <el-table-column type="expand">
              <template slot-scope="scope">
                <!-- 循环创建标签 -->
                <el-tag
                  v-for="(item, i) in scope.row.attr_vals"
                  :key="i"
                  closable
                  @close="handleClosed(i, scope.row)"
                >
                  {{ item }}
                </el-tag>
                <!-- 动态编辑标签 -->
                <el-input
                  class="input-new-tag"
                  v-if="scope.row.inputVisible"
                  v-model="scope.row.inputValue"
                  ref="saveTagInput"
                  size="small"
                  @keyup.enter.native="handleInputConfirm(scope.row)"
                  @blur="handleInputConfirm(scope.row)"
                >
                </el-input>
                <el-button
                  v-else
                  class="button-new-tag"
                  size="small"
                  @click="showInput(scope.row)"
                  >+ New Tag</el-button
                >
              </template>
            </el-table-column>
            <el-table-column type="index"></el-table-column>
            <el-table-column
              label="参数名称"
              prop="attr_name"
            ></el-table-column>
            <el-table-column label="操作">
              <el-button type="primary" size="mini" icon="el-icon-edit">
                编辑
              </el-button>
              <el-button type="danger" size="mini" icon="el-icon-delete">
                删除
              </el-button>
            </el-table-column>
          </el-table>
        </el-tab-pane>
      </el-tabs>
    </el-card>

    <!-- 添加参数对话框 -->
    <el-dialog
      :title="'添加' + textTitle"
      :visible.sync="addDialogVisible"
      width="50%"
      @close="addDialogClosed"
    >
      <el-form
        :model="addForm"
        :rules="addFormRules"
        ref="addFormRef"
        label-width="100px"
      >
        <el-form-item :label="textTitle" prop="attr_name">
          <el-input v-model="addForm.attr_name"></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer" class="dialog-footer">
        <el-button @click="addDialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="addParams">
          确 定
        </el-button>
      </span>
    </el-dialog>
  </div>
</template>

<script>
export default {
  data() {
    return {
      cateList: [],
      // 选中的商品分类 id
      selectedKeys: [],
      // 商品分类级联选择器的配置项
      cateProps: {
        expandTrigger: 'hover',
        label: 'cat_name',
        value: 'cat_id',
        children: 'children'
      },
      //
      activeName: 'many',
      // 动态参数的数据
      manyTableData: [],
      // 静态属性的数据
      onlyTableData: [],
      // 控制添加参数对话框的显示与隐藏
      addDialogVisible: false,
      // 添加参数表单数据
      addForm: {
        attr_name: ''
      },
      // 添加参数表单规则
      addFormRules: {
        attr_name: [{ required: true, message: '请输入参数', trigger: 'blur' }]
      }
    }
  },
  methods: {
    // 获取商品分类列表
    async getCateList() {
      const { data: res } = await this.$http.get('categories')
      if (res.meta.status !== 200) {
        return this.$message.error('获取商品分类列表失败！！！')
      }
      this.$message.success('获取商品分类列表成功！！！')
      this.cateList = res.data
    },
    // 级联选择框选中项变化会触发这个函数
    handleChange() {
      // 选中的不是第三级分类
      if (this.selectedKeys.length !== 3) {
        this.selectedKeys = []
        // 清空表格数据
        this.manyTableData = []
        this.onlyTableData = []
        return
      }
      // 选中的是第三级分类，获取参数列表
      this.getParamsData()
    },
    // tab 页签点击事件的处理函数
    handleTabClick() {
      // 切换页签时，获取相应参数
      this.getParamsData()
    },
    // 获取参数列表
    async getParamsData() {
      // 发送请求，获取参数列表
      const { data: res } = await this.$http.get(
        `categories/${this.cateId}/attributes`,
        {
          params: { sel: this.activeName }
        }
      )
      if (res.meta.status !== 200) {
        return this.$message.error('获取参数列表失败！！！')
      }

      res.data.forEach(item => {
        item.attr_vals = item.attr_vals ? item.attr_vals.split(' ') : []
        // 控制文本输入框与按钮的显示与隐藏
        item.inputVisible = false
        // 文本框中输入的内容
        item.inputValue = ''
      })

      // 根据参数类型分配数据
      if (this.activeName === 'many') {
        this.manyTableData = res.data
      } else {
        this.onlyTableData = res.data
      }
    },
    // 监听添加参数对话框的关闭事件，重置表单
    addDialogClosed() {
      this.$refs.addFormRef.resetFields()
    },
    // 点击对话框的确定按钮，添加参数，刷新参数列表
    async addParams() {
      this.$refs.addFormRef.validate(async valid => {
        if (!valid) return
        const { data: res } = await this.$http.post(
          `categories/${this.cateId}/attributes`,
          {
            attr_name: this.addForm.attr_name,
            attr_sel: this.activeName
          }
        )
        if (res.meta.status !== 201) {
          return this.$message.error('添加参数失败！！！')
        }
        this.$message.success('添加参数成功！！！')
        this.addDialogVisible = false
        this.getParamsData()
      })
    },
    // 按下 enter 键或文本框失去焦点时触发
    handleInputConfirm(row) {
      if (row.inputValue.trim().length === 0) {
        row.inputValue = ''
        row.inputVisible = false
        return
      }
      // 有输入内容
      row.attr_vals.push(row.inputValue.trim())
      row.inputValue = ''
      row.inputVisible = false
      // 发起请求，提交参数
      this.saveParams(row)
    },
    // 点击 +New Tag 按钮时触发（显示文本框）
    showInput(row) {
      row.inputVisible = true
      // 让文本框自动获得焦点
      // $nextTick 方法的作用：当页面上的元素被重新渲染之后，才会指定回调函数中的代码
      this.$nextTick(_ => {
        this.$refs.saveTagInput.$refs.input.focus()
      })
    },
    // 监听标签的删除事件
    handleClosed(i, row) {
      row.attr_vals.splice(i, 1)
      this.saveParams(row)
    },
    // 发送请求，保存修改的参数
    async saveParams(row) {
      const { data: res } = await this.$http.put(
        `categories/${this.cateId}/attributes/${row.attr_id}`,
        {
          attr_name: row.attr_name,
          attr_sel: row.attr_sel,
          attr_vals: row.attr_vals.join(' ')
        }
      )
      if (res.meta.status !== 200) {
        return this.$message.error('添加参数失败！！！')
      }
      this.$message.success('添加参数成功！！！')
    }
  },
  created() {
    this.getCateList()
  },
  computed: {
    // 如果按钮需要被禁用则返回 true，否则返回 false（级联选择器选中第三级分类时）
    isBtnDisabled() {
      if (this.selectedKeys.length !== 3) {
        return true
      }
      return false
    },
    // 当前选中的三级分类的 ID
    cateId() {
      if (this.selectedKeys.length === 3) {
        return this.selectedKeys[2]
      }
      return null
    },

    textTitle() {
      if (this.activeName === 'many') {
        return '动态参数'
      }
      return '静态属性'
    }
  }
}
</script>

<style lang="less" scoped>
.cate_opt {
  margin: 15px 0;
}

.el-cascader {
  width: 150px;
}

.el-tag {
  margin: 10px;
}

.input-new-tag {
  width: 120px !important;
}
</style>
